package com.example.aspect;

import com.example.anno.AutoFill;
import com.example.constant.AutoFillConstant;
import com.example.enums.OperationType;
import com.example.utils.ThreadLocalUtil;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;
import java.time.LocalDateTime;
import java.util.Map;

/**
 * 自定义切面，实现公共字段自动填充处理逻辑
 */
@Slf4j
@Aspect
@Component
public class AutoFillAspect {

    /**
     * 切入点
     */
    @Pointcut("execution(* com.example.mapper.*.*(..)) && @annotation(com.example.anno.AutoFill)")
    public void autoFillPointCut() {
    }

    @Before("autoFillPointCut()")
    public void autoFill(JoinPoint joinPoint) {
        log.info("开始进行公共字段自动填充...");

        // 获取到当前被拦截的方法上的数据库操作类
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        AutoFill autoFill = signature.getMethod().getAnnotation(AutoFill.class);
        OperationType operationType = autoFill.value();

        // 获取当前被拦截的方法的参数--实体对象
        Object[] args = joinPoint.getArgs();
        if (args == null || args.length == 0){
            return;
        }

        Object entity = args[0];

        // 准备赋值的数据
        LocalDateTime now = LocalDateTime.now();
        Map<String, Object> map = ThreadLocalUtil.get();
        Integer userId = (Integer) map.get("id");

        // 根据当前不同的操作类型，为对应的属性进行赋值
        if (operationType == OperationType.INSERT) {
            // 为四个字段赋值
            try {
                Method setCreateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_TIME, LocalDateTime.class);
                Method setCreateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_USER, Integer.class);
                Method setUpdateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_TIME, LocalDateTime.class);

                // 通过反射为对象属性赋值
                setCreateTime.invoke(entity, now);
                setCreateUser.invoke(entity, userId);
                setUpdateTime.invoke(entity, now);

            } catch (Exception e) {
                e.printStackTrace();
            }
        } else if (operationType == OperationType.UPDATE) {
            try {
                // 为两个字段赋值
                Method setUpdateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_TIME, LocalDateTime.class);
                // 通过反射为对象属性赋值
                setUpdateTime.invoke(entity, now);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    }
}
